Introducing and simulation of two emerging stabilizer mechanisms for trajectory tracking of quadrotor UAVs under disturbance conditions: cross and pendulum stabilizing mechanisms

A vertical take-off and landing (VTOL) aircraft is one that can hover, take off, and land vertically. VTOL UAVs have high maneuverability and their users are after maintaining this maneuverability. This alongside with their extreme nonlinearities and under actuating control system rises the importance of the control of flight. In this paper, the effect of using stabilizing mechanisms in trajectory tracking of quad-rotor unmanned aerial vehicles under wind gusts is studied. Two mechanisms that are simulated and used in this paper are very rare and introduced their usage for first time in this study. The first one is a spherical pendulum stabilizer and the second one is a cross stabilizer. Also appropriate controller is designed for each stabilizer mechanism. The performance of the systems are investigated in the presence of disturbing forces. The results show that instead of using complicated nonlinear control methods, the proposed stabilizer mechanism yields a desired performance. Acceptable trajectory tracking shows the successful effectiveness of the proposed stabilizers.